Formulas all changed to relative cell references - why and how?

[Ninja97]

I've been using a spreadsheet I created 5 years ago, which has grown and evolved the entire time. I use long and complicated formulas, many of which make heavy use of arrays, using INDEX and MATCH.

I had to look at one of my formulas today, and noticed that NONE of my formulas are as they were entered. This has recently changed, and I don't know why.

Here is an example of one of them:
=INDEX('BBA Pricing'!R6C1:R141C7,MATCH(R[-34]C[-7]&R[-34]C[-6]&R[-34]C[-5]&R[-34]C[-4]&R[-34]C[-3]&R[-34]C[-2],'BBA Pricing'!R6C[-9]:R141C[-9]&'BBA Pricing'!R6C[-8]:R141C[-8]&'BBA Pricing'!R6C[-7]:R141C[-7]&'BBA Pricing'!R6C[-6]:R141C[-6]&'BBA Pricing'!R6C[-5]:R141C[-5]&'BBA Pricing'!R6C[-4]:R141C[-4],0),7)

That is NOT how it has read for the last 5 years. I know it still works the way it always has, but don't want it to read like this. I can't understand it in this form. Can anybody tell me how to make my formulas read the way they were typed?

 

[AlanY]

the formula style was changed to R1C1 style, to change it back go to File > Option > formula and uncheck R1C1 style

 

[RoryA]

In Excel options, in the Formulas section make sure the option to use R1C1 referencing is not checked.

 

[Ninja97]

Thanks, that worked. But I know I never turned that on. Do you know of any unrelated actions that result in that automatically getting turned on?

 

[RoryA]

There isn't a shortcut key that I'm aware of, so I'd guess some code did it.